In the technical field of photography, it is well known to use various kinds of polymers as a mordant for the purpose of preventing undesired migration of dyes. U.S. Pat. Nos. 4,131,469, 4,147,548 and 4,308,335, German Patent Application (OLS) No. 2,941,818 and Japanes Patent Application (OPI) Nos. 30328/78 and 17352/81 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application") disclose polymeric mordants.
In addition, British Pat. Nos. 2,011,912 and 2,093,041 and U.S. Pat. No. 4,282,305 disclose polymer mordants which exhibit less chemical change or decomposition of dye images under irradiation by light. However, these polymer mordants are poor in the mordantability, and, therefore, the time to be required for the transfer of dyes is extremely long, which is a very serious defect in the application of the polymer mordants to the field of instant color photography. Further, dyes are apt to be desorbed and are diffused because of the somewhat poor mordantability of the polymer mordants, resulting in poor sharpness of images; this is another defect.
On the other hand, U.S. Pat. No. 3,898,088 described water-insoluble mordants containing a quaternary nitrogen atom having a substituent with a large number of carbon atoms; and U.S. Pat. Nos. 3,958,995 and 4,193,800 describe polymer latex mordants which are insolublized in water. These mordants have higher dye retentivity when they contain a quaternary nitrogen atom having a substituent with a larger number of carbon atoms, and further, the diffusion of dyes is less in such a case.
However, it has been found that the color images as mordanted with mordants of these kinds become cloudy if the water derived from a treating solution is not completely dried (i.e., in a so-called wet state) with the results of a lowering of the density of the color images and the occurrence of blur. In other words, the image quality of the color images becomes poor, for example, as if pictures are looked at through a ground glass. This phenomenon is especially remarkable in integral imaging receiver type photographic elements of low drying speed and becomes more pronounced within about two weeks after the photographic image is formed, and this is a fatal defect in an instant color photography which is characterized by the high rapidity of the formation of images.
It is noted that the cloud in a wet state is apt to be higher in the case of the use of mordants of higher color retentivity (mordantability), and therefore, the use of a strong mordant which contains a quaternary nitrogen atom having a substituent with a large number of carbon atoms results in a reciprocal relationship between the mordanting ability of the mordant and the cloud of the image formed. In order to obtain photographic materials capable of forming images of high sharpness and resolving power, it is essential that the mordants to be used in the materials are to have high mordanting ability, and therefore, it has heretofore been strongly desired to solve the problem of the aforementioned reciprocal relationship.